Remote Measurement of the Pipe Thickness Reduction by Microwaves

Abstract

A method which can inspect a pipe in a large scale and measure the thickness reduction remotely was demonstrated. A copper pipe having 17 mm inner diameter, 1 mm wall thickness, and 900 mm length was measured. The thickness reduction having the value from 10% to 80% of the wall thickness was detected significantly. By building up a resonance for the microwave signal propagated in the pipe, it is possible to determine the thickness reduction using the measured resonance frequency.